GrandCentral.com by Google (GrandCentral: The New Way to Use Your Phones) (US Numbers)
*NOT ACCEPTING NEW REGISTRATION or NEW INVITES AS OF 11/22/2008*
-You get a US number (just about any state)
-You need a US/Cad number to complete the verification
-If you live outside North America you may need a proxy to complete the registration, or have a friend in NA set it up for you (mixed info on this)
-You can set it to forward to up to 6 different numbers (US or CAD numbers only)
-You can have it ring your Gizmo Number (1-747)
-You can have personalized Voice messages for your contacts, by groups, individually, etc.
-They have CallMe buttons, so someone can ring you up from the web: They enter their number, it calls them, calls you, and you are talking.
-Free calls and forwarding to US/Canada
-It is still in beta and everything right now is free.How to Use: Forwards directly to your US/Cad/Gizmo number

GoogleVoice (http://www.google.com/voice)
*Currently open only to current GrandCentral users
-The rebranded GrandCentral service
-All same services as GrandCentral
-Has Voice to Text transcription for Voicemail
-Can send and receive SMS messages
-Forwards and calls to US are free, whereas there is a cost for Canada and elsewhere
-Has option to call your GV number and call out using the serviceHow to Use: Forwards directly to your US/Gizmo number

OrbTalk (PAYG | Orbtalk)
-Real geographic UK numbers just about everywhere in UK including London 020 7 numbers.How to Use: ATA or VoXalot/PBXes/MySipSwitch

EuteliaVoip-Formerly Skypho (EUTELIA)
-Free real numbers in most of Italy
-Free real numbers in most of UK
-Free real numbers in Bucharest, Romania +40-21 range (however the Romanian numbers are buggy from my experience)
-Good news is that you can get up to 15 different numbers, but each of them needs to be registered on its own so you need either 15 different lines on an ATA or a place like VoXalot/PBXes/MySipSwitch to have them all pointed to one place. I have been using MySipSwitch for these with good results pointing them to my current VSP.How to Use: ATA or VoXalot/PBXes/MySipSwitch (see note)

BlueSip (blueSIP - Business Class VoIP)
-Free Munich, Germany number (format +49 89 72xxxx xxxxx)
-Complete registration, be aware that the username to use for registration is of the format bluesip/userHow to Use: ATA or VoXalot/PBXes/MySipSwitch

Hol (www.hol.gr)
***FREE NUMBERS FROM HOL ARE NO LONGER AVAILABLE***
-Free real number in Athens, Greece (+30-213 range) or Thessaloniki (+30-231)
-To Register go to: http://public.curbas.hol.gr/register...-register1.cgi
-As you're going through registration, at the top of the page, you'll see an option to have the registration form in English
-They are picky about the password you choose (it must have a symbol: #$% and a letter at least)
-You'll then receive an email with a link to continue the regitration further.
-To login Go to https://myaccount.curbas.hol.gr/auth/login.cgi
-Once logged in click on the RED MyAccount bar on the side of the page
-Near the bottom of the page you'll see eVoice basic (get User/Pass you need to SIP Register)
-The server is evoice.hol.gr
-I had success using them with PBXes (not tried VoXalot/MySipSwitch)How to Use: ATA or VoXalot/PBXes/MySipSwitch (see note)

OpenTelecom (OpenTelecom - Products and Services)
-Free UK Non-Geographic Numbers: 0844 0845 0871 070.
-Takes them a while to reply, and depending on the number you choose, you can forward it to various destinations (you may want to get a UK geographic number first from OrbTalk, and have this numbers forwarded there, since OpenTelecom does not seem to support SIP URI forwarding).

1. Some DID Providers (including the ones above) offer forwarding to your current SIP URI, YourVoipUsername@YourProviderProxy

OR

2.MySipSwitch.com
Go to My SIP Switch Use multiple VoIP providers with one SIP phone, and create an account. Ignore the dialing plans, but go to the bottom of the Config Page when logged in. Fill out the provider info, and under 'contact' put where you want it to ring YourVoipUsername@YourProviderProxy

3.VoXalot.com(Voxalot - Home) (Cost: Starting at $15/year)
-You need to perform a SIP Registration
-If you want the number to ring somewhere else (not VoXalot) use their forwarding features.

4. PBXes.com
-Although slightly complicated, it can achieve forwarding as well

WorkArounds: Make and Receive SIP/VoIP Calls from your Cell/Landline (No equipment needed)*note: you may want to read throughout this post for a number of free options before getitng started with a guide

Receiving Calls via VoIP on your regular PSTN Phone: People from around the world call a number local to them, then enter an extension when prompted which in turn rings your CellPhone or HomePhone.

There are now 4 options, all of which achieve similar results, but at different costs and qualities:

There is two things two consider with each setup (in my opinion), reliability and voice quality.
This remains my opinion, but the paid VoXalot option (3) produces best results with both, unfortunately it is no longer free. The next best one is the current number (1), quality is rather good, and it is free.

Making VoIP Calls from your regular PSTN Phone

1. To call any Voip User for which you have a Network Number (eg. a Gizmo/FWD/VoXalot/CallCentric number etc..):
-Dial SipBroker Access Number local to you (SIPBroker - PSTN Numbers)
-When prompted enter *SipCode (find here SIPBroker - Provider White Pages) followed by the network number. eg.*747-1747xxxxxxx

2. To Call an ENum number or a Toll-Free number (a Toll Free number not reachable from your location normally)
-Dial SipBroker Access Number local to you
-When prompted enter the full number in Country Code-Number format for an ENum call (you can also use *013-Country Code-Number)
-For North American Toll-Free Numbers simply call in *1-800-xxx-xxxx format
-All other Toll Free Numbers, including NA Toll Free numbers can also be called in CountryCode-Number format

What numbers can I call for free via ENum: Any number that has an associated ENum record, search here: SIPBroker - ENUM Lookup

Earthcaller (Jaduka)
***EarthCaller OPERATION MAY HAVE CEASED***
-US and CANADA
-It works directly from the web
-It needs to instal an ActiveX script
-You need to use a Headset/Mic to talk from your computer
-It also requires you to complete a Free Jaduka Labs Registration

CallingAmerica (Free phone calls with Calling America)
-US and CANADA
-It works directly from the web
-You can register & login for unlimited calls
-You need to use a Headset/Mic to talk from your computer

AdPhone (ADPHONE)
-MANY COUNTRIES
-Download SoftPhone
-Complete Registration
-Get 2 minutes free per call , up to a total of 30 minutes per day. You cannot call the same number for free more than once every 10 minutes.

Free Calls to Members' phones

PhoneGnome.com (PhoneGnome - Free Calls to Regular Phones, Your Way)
-You register your Home or Cell Number (assuming you are not buying a box from them).
-You can make and receive free calls to Members' phones in these Countries: Qualifying International Numbers
-If you set up the software (SIP based), it'll ring there, but your phone will also ring.
-The call is free for the person placing the call.
-The CID appearing (if using the cellphone) may or may not be local.

Jajah.com (JAJAH - web-activated telephony)
-Web based calling software.
-Allows free calls between members with some country restrictions: JAJAH - web-activated telephony (check bottom of page there).
-In order to use this, you must top up your account once in while (you'll be able to call other members for free after having topped up the first time)

Both parties need to call in to a local Access Number

Rebtel.com (Cheap international calls - Rebtel provider - Rebtel)
-Geared towards mobiles.
-You make an account.
-You add a friend's number.
-It gives you a local access number to call that will ring your friend.
-When the other guy receives your call, he sees a CID in his screen.
-He has to pick up, then hang up within 10 sec and call that CID, while you wait on the line (if you don't want to go through the hang up process, you gotta buy minutes from them).
-Finally you connect and the call is local for both of you. It works with international contacts too.
-Their Explanation: International calling explained â€“ Rebtel

Talkster (Talkster free international calling)
-No need for accounts
-Enter your number, and your friends number
-It gives you a number local to you for your friend, and a number local to your friend for you
-Call your friend and tell him to hang up, and call you back on the assigned number while you wait on the line
-Both of you are calling numbers local to you and talking to each other...
-See their explanation Talkster free international calling or Talkie Video

Other

Jaduka MyPrivateLine+Click&Connect (Jaduka: Your web is calling!)
***SERVICE HAS BEEN DISCOUNTINUED***
-MyPrivateLine gives you a 1800 number + Extension that can be pointed to any US/Cad number
-Click and Connect provides a web button which people can click to call you
-Both include 60 minutes for free.
-Can be used for free calls by pointing either account to the number you wnat to call.

2. BetaMax Services
Betamax offers a number of services, that on first appearance look different, yet follow the same model. Keep in mind that transferring credit from one to the other is not possible. Their free calling lists change constantly, and they are different from one service to the next. When considering each service look for the following:

-Rates to the Country of your Choice
-List of Free Countries
-Credit Expiry Period
-FreeDay Weekly Minute limit/FreeDay Expiry period
-Can it be used with software
-Can it be used with a SIP Device
-Any WebBased services

VoipRaider.com
Credit Expiry: Never
FreeDays: Unspecified Minutes/week/120 Days (*in order to call a person in one of the free destinations, you have to add this person to your contact list )
Software: Yes
SIP: Yes (sip.VoipRaider.com)
(Reported issues with using SIP for calling, SIP calls are charged higher and calls that are supposed to be free may actually be charged when using SIP)

Note: Please be careful with Betamax services, they are known to have billing issues. Personally I would suggest paying with PayPal, and funding the PayPal payment with a credit card (giving yourself at least two dispute resolution possibilities, PayPal and your CC company, while avoiding having your credit card charged continuously)

They provide a hosted Asterisk based PBX service. Their interface remains faithful to the Asterisk interface in general, although it is much more user friendly. Their services include:

PBXes Free: The Free account notable limits are a 10 GB usage, and 2 simultaneous calls, with a 60 min cutoff, and the unability to post in the support forums.PBXes Premium: Includes a full on PBX including among others Fax as EMail,a full AutoAttendant and Que system, and CallBack access to your TrunksPBXes Pro: Is geared towards businesses, providing a hosted PBX which can be customized for various clients, including much of the same features as the Premium acct.

MySipSwitch is a PBX service concerned solely with Call Routing. In avoiding the hadling of the actual audio stream their application runs much lighter. It is currently an R&D base being run by two technicians and sponsored by BlueFace.ie It provides the following fetaures:

(always type number in international format)
PSTN calls are not free, but you can now add your own providers to GTalk2Voip, and the call will be routed through them. Otherwise GTalk2Voip routes through its own providers and requires you have a balance
-When calling someone for the first time using the commands above, chances are it will not go through, but they will receive a notice that service@gtalk2voip.com has added them as a friend, if they accept, the second time you try they will receive a call from service@gtalk2voip.com
-This works much smoother in GoogleTalk, rather than MSN (have not tested with Yahoo)
-They assign you a number *018xxxxx, that can be reached by dialing SipBroker Access Number + *018xxxxx
or *018xxxxx@sipbroker.com (SIP URI calling), in all this cases you'll receive a call on your MSN/Yahoo/GTalk messenger
-You can also get a DID number, forward it to *018xxxxx@sipbroker.com, and your MSN/GTALK/YAHOO messenger will ring when someone calls you
-There is a generic Voicemail if you don't pick up, or you can forward to a SIP URI and receive calls to your current provider
-You can use them to IM people not using same messenger (Voice-over-IP gateway for Google Talk, MSN and Yahoo Users)
-You can create your own WebCall button (it calls you via Voip, plus uses one of your providers to call the other party and connect you together, if someone enter an actual number though, you will end up paying for the call, but at VoIP rates) (Voice-over-IP gateway for Google Talk, MSN and Yahoo Users)
-In Summary, neat to play around with. It is a raw framework for now, not very user friendly, but looks promising.

VoIP Networks/Other

FWD: Free World Dialup (FWD | Home)
***FWD is now subscription based***
-Free Calling between Members on their Network
-Can be used with their SoftPhone/Other SoftPhones/ VoIP adapter
-IM other FWD members, SIP-Users, AIM/MSN/Yahoo/GTalk/Skype/ICQ (FWD | Help)
-Call other Voip Users on other networks
-Receive Calls from PSTN using access numbers (only 2 numbers really)
-VoiceMail
-They plan to be offering paid FWDout/FWDin service soon
-From personal testing the FWD Communicator, and adding IM contacts from other networks is glitchy.

Gizmo Project/ SipPhone (Gizmo – A free phone for your computer / SIPphone - Call worldwide over your Internet connection with any phone)
-Use with their SoftPhone/Others/Voip Adapter
-More aimed at putting together IM and Voip
-Free Calls to other members
-You are assigned a 1-745 number (only valid within Gizmo, not from outside)
-Can get a free 775 area code PSTN nummber (but requires a credit card and US adress)
-Gizmo All Calls Free plan (Gizmo – A free phone for your computer - Help)
If you have a friend that you regularly call or chat on Gizmo, once in a while when he/she is not on you can call their cell/home number for free. Both of you have to have Active status for All Calls Free
-Claims to let you message and call MSN/GoogleTalk/Yahoo/AIM/Jabber/SIP users (this works some times and not others; from my experimenting MSN is the most problematic)
-Is offering paid Outgoing Minutes/Incoming Numbers

TPad (Tpad - The Global Phone Network)
-Free calls to other TPad users
-Use SoftPhone/Voip Adapter
-Gotta pay for outgoing calls to real numbers
-Can receive calls from other Users, or by someone dialing Access Numbers + TPad number
-Includes Voicemail Service
-The biggest plus is their access numbers in countries where it is commonly hard to find one.
-Mentioned in the WorkAround above for local calls to your Cell/Home from around the world

Feel free to make suggestions, comments or anything else you think may be useful. I will try to correct mistakes, and keep things updated.

BTW, this are some other services I am hoping to look into, but if someone already has experience with them, feel free to post a quick summary:

Also, the other thing to keep in mind is that it seems VoXalot is going premium, so the forwarding service the Workaround is using will not be free after July 16

Yes this is a problem for me also.

I use 4 VoXaLot accounts.

One for each of my ATA ports. One permidently forwarded to my externally hosted conference line, and one for a WiFi/SIP enabled mobile that I plan to get.

There is no way I can justify US$100 a year to have VoXpremium for all 4 accounts.

So now I am looking for alternatives.

- I need to be able to forward for free externally one sipbroker prefixed number to my conference line.
- register with my VSP for incomming's from my DID.
- Support SipBroker codes locally here when dialing.
- Enum support.

Looks like I will have to start from scratch again with my local VoIP setup.

i didnt register phonegnome when i added it as provider if that's what you mean. phonegnome voicemail is off.

There are a few basic things to check:

In PhoneGnome:

-Under Features your Remote Calls is active and checked to ring both Home and SoftGnome (press Edit to get here)
-In the same page under SIP Settings are the ettings you should be using in VoXalot.
-In the HomePage of your PhoneGnome account, note how your number appears (better yet keep that page open)

In VoXalot:

-In Member Details leave everything as is, except deactivating VoiceMail
-In Providers, add PhoneGnome under providers setting Active and Register to No, and Codecs to ulaw;alaw;g726;g729;ilbc;gsm
-Under Call Forward, leave everything as is, choose phone number, then enter the phone you registered in phonegnome. Try first just the number,no country code, no spaces, no dashes. If that doesn't work try Country code + Number, or the way someone within your country would dial your number to call you. Naturally the provider for the forward is PhoneGnome.

Now Dialing:

Call one of the SipBroker PSTN Numbers. After it says welcome etc. enter
*010123456 (where 123456 is your VoXalot Number).

If still having problems, the way to troubleshoot is check in PhoneGnome under Call Summary, Placed Calls and see if anything is being dialed, and how it's being dialed.

Hope it helps...

BTW, explain a bit more how GrandCentral comes into the mix for you. From all my testing I have not been able to combine GrandCentral or PhoneGnome....